soundness vs substance

soundness

noun
  • The property (of an argument) of not only being valid, but also of having true premises. 

  • The result or product of being sound. 

  • The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever T⊢𝜙 is true, then T vDash 𝜙 must also be true, for any wff φ of logic L. 

  • The state or quality of being sound. 

substance

noun
  • Substantiality; solidity; firmness. 

  • Physical matter; material. 

  • Material possessions; estate; property; resources. 

  • Hypostasis. 

  • Drugs (illegal narcotics) 

  • The essential part of anything; the most vital part. 

  • A form of matter that has constant chemical composition and characteristic properties. 

verb
  • To give substance to; to make real or substantial. 

How often have the words soundness and substance occurred in a corpus of books? (source: Google Ngram Viewer )